It's not complicated
"we are searching in a very respectful way with the United Kingdom ... for a solution"
The solution is to show him the door. He will be arrested, his alleged crimes investigated, and then he will be either prosecuted or released depending on the results. That's how the justice system works, both in the UK and Ecuador. The only part of the whole thing lacking in respect is hiding a common criminal for 5 years for no apparent reason.